Pressure application apparatus and pressure application method

ABSTRACT

A pressure application technique is provided that enables two objects to be pressurized (e.g., objects to be bonded) to be positioned with greater accuracy before having pressure applied thereto. The objects to be pressurized are moved relative to each other in a Z direction such that the objects are brought into contact with each other (step S 13 ). Then, a horizontal positional shift ΔD between the objects to be pressurized is measured in the contact state of the objects to be pressurized (step S 14 ). Thereafter, positioning of the objects to be pressurized is again performed by moving the objects to be pressurized relative to each other in the horizontal direction, as a result of which the positional shift ΔD is corrected (step S 17 ).

This is a Continuation application of Ser. No. 13/386,788, filed Jan.14, 2012.

TECHNICAL FIELD

The present invention relates to a technique for applying pressure totwo objects to be pressurized.

BACKGROUND OF THE INVENTION

There is technology for bonding two objects to be bonded together. Forexample, Patent Document 1 describes a mounting apparatus (bondingapparatus) that bonds a component held by a head and a substrate held ona stage together so that the component is mounted on the substrate. Notethat such a technique is also referred to as a technique for bonding twoobjects to be pressurized (objects to be bonded) together by applyingpressure.

In such an apparatus, firstly, the positions (specifically, horizontalpositions) of two objects to be bonded that are not in contact with eachother are detected. Then, positioning (alignment) is performed based onthe detection result of the horizontal positions of the objects to bebonded, so as to eliminate a shift in the relative positions of theobjects to be bonded in the horizontal direction. Thereafter, theobjects to be bonded are brought closer to and then into contact witheach other, so that the objects to be bonded are bonded together.

However, the above-described technique has problems such as that apositional shift can occur due to various factors when two objects to bebonded that are not in contact with each other are brought into contactwith each other. For example, the horizontal positions of the objects tobe bonded may be shifted slightly by the action of physical impact forcegenerated when the objects to be bonded are brought into contact witheach other.

Development of fine processing technology in recent years is creatingsituations where such a positional shift cannot be tolerated.

PRIOR ART DOCUMENTS

Patent Document 1 JP 2008-85322A

SUMMARY OF THE INVENTION

The purpose of the present invention is to provide a pressureapplication technique that enables two objects to be pressurized (e.g.,objects to be bonded) to be positioned with greater accuracy beforehaving pressure applied thereto.

In order to solve the above-described problems, a first aspect of thepresent invention relates to a pressure application apparatus thatapplies pressure to objects to be pressurized including a first objectto be pressurized and a second object to be pressurized. The pressureapplication apparatus includes relative movement means for moving thefirst object to be pressurized and the second object to be pressurizedrelative to each other in a predetermined direction, first measurementmeans for measuring a positional shift between the first object to bepressurized and the second object to be pressurized in a planeperpendicular to the predetermined direction, in a state in which theobjects to be pressurized are in contact with each other by the relativemovement operation performed by the relative movement means, andalignment means for performing positioning of the objects to bepressurized, by correcting the positional shift.

A second aspect of the present invention relates to a pressureapplication method for applying pressure to objects to be pressurizedincluding a first object to be pressurized and a second object to bepressurized. The pressure application method includes the steps of: a)moving the first object to be pressurized and the second object to bepressurized relative to each other in a predetermined direction suchthat the first object to be pressurized and the second object to bepressurized are brought into contact with each other, b) measuring apositional shift between the first object to be pressurized and thesecond object to be pressurized in a plane perpendicular to thepredetermined direction, in a state in which the objects to bepressurized are in contact with each other, and c) performingpositioning of the objects to be pressurized, by correcting thepositional shift.

A third aspect of the present invention relates to a pressureapplication apparatus that applies pressure to objects to be pressurizedincluding a first object to be pressurized and a second object to bepressurized with a fluidizable substance layer sandwiched between theobjects to be pressurized. The pressure application apparatus includesrelative movement means for moving the first object to be pressurizedand the second object to be pressurized relative to each other in apredetermined direction, first measurement means for measuring apositional shift between the objects to be pressurized in a planeperpendicular to the predetermined direction, in a contact state inwhich the first object to be pressurized and the fluidizable substancelayer adhering to the second object to be pressurized are in contactwith each other by a relative movement operation performed by therelative movement means, and alignment means for performing positioningof the objects to be pressurized, by correcting the positional shift.

A fourth aspect of the present invention relates to a pressureapplication method for applying pressure to objects to be pressurizedincluding a first object to be pressurized and a second object to bepressurized with a fluidizable substance layer sandwiched between theobjects to be pressurized. The pressure application method includes thesteps of: a) moving the objects to be pressurized relative to each otherin a predetermined direction such that the first object to bepressurized and the fluidizable substance layer adhering to the secondobject to be pressurized are brought into contact with each other, b)measuring a positional shift between the objects to be pressurized in aplane perpendicular to the predetermined direction, in a state in whichthe first object to be pressurized and the fluidizable substance layeradhering to the second object to be pressurized are in contact with eachother, and c) performing positioning of the objects to be pressurized,by correcting the positional shift.

With the present invention, it is possible to correct a positional shiftdue to contact and to thereby position two objects be pressurized withgreater accuracy before having pressure applied thereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view showing the internal structure of a bondingapparatus.

FIG. 2 is a side view showing the internal structure of the bondingapparatus.

FIG. 3 is a schematic perspective view showing the vicinity of a stageand a head.

FIG. 4 is a diagram showing two alignment marks added to one of objectsto be bonded.

FIG. 5 is a diagram showing two alignment marks added to the other ofthe objects to be bonded.

FIG. 6 is a diagram showing a captured image of the objects to bebonded.

FIG. 7 is a diagram illustrating a state in which a pair of marks areshifted from each other.

FIG. 8 is a flowchart showing an operation according to a firstembodiment.

FIG. 9 is a diagram showing a situation in which two objects to bebonded are correctly disposed (in a non-contact state).

FIG. 10 is a diagram showing a situation in which two objects to bebonded are correctly disposed (in a contact state).

FIG. 11 is a diagram showing a situation in which two objects to bebonded are disposed at an angle to each other.

FIG. 12 is a diagram showing a situation in which two objects to bebonded start to come into contact with each other on one end sidethereof.

FIG. 13 is a diagram showing a situation in which two objects to bebonded are in contact with each other in a state following a horizontalpositional shift therebetween.

FIG. 14 is a diagram showing a situation in which an alignment operationis performed after a state of contact between two objects to be bondedis temporarily released.

FIG. 15 is a diagram showing a captured image of a mark acquired with asmall amount of blurring.

FIG. 16 is a diagram showing a captured image of a mark acquired with arelatively large amount of blurring.

FIG. 17 is a diagram illustrating an in-focus state at the time ofcapturing alignment marks.

FIG. 18 is a flowchart showing an operation according to a secondembodiment.

FIG. 19 is a schematic diagram illustrating a contact operation in astate following deviation in parallelism.

FIG. 20 is a schematic diagram illustrating a contact operationperformed while accompanying deviation in parallelism.

FIG. 21 is a diagram illustrating a contact operation performed whileaccompanying deviation in parallelism.

FIG. 22 is a diagram showing the relationship between a horizontalpositional shift amount ΔD and a Z-position correction amount ΔZ.

FIG. 23 is a flowchart showing an operation according to a thirdembodiment.

FIG. 24 is a diagram showing a situation in which a positional shiftbetween two objects to be bonded is corrected while maintaining a stateof contact therebetween.

FIG. 25 is a flowchart showing an operation according to a fourthembodiment.

FIG. 26 is a diagram showing a change in the temperature of a head.

FIG. 27 is a diagram showing a state in which there is a positionalshift.

FIG. 28 is a diagram showing a situation in which horizontal positioningof two objects to be bonded is executed in a state in which metal bumpsare melted.

FIG. 29 is a diagram showing a situation in which horizontal positioningof two objects to be bonded is executed in a state in which metal bumpsare melted.

FIG. 30 is a diagram showing a pressure application apparatus accordingto a fifth embodiment.

FIG. 31 is a schematic perspective view showing the vicinity of a stageand a head.

FIG. 32 is a plan view showing the vicinity of the head.

FIG. 33 is a flowchart showing an operation according to the fifthembodiment.

FIG. 34 is a diagram showing a situation in which two objects to bepressurized are correctly disposed (in a non-contact state).

FIG. 35 is a diagram showing a situation in which two objects to bepressurized are brought into contact with each other while accompanyinga positional shift therebetween.

FIG. 36 is a diagram showing a situation in which two objects to bepressurized are correctly disposed (in a contact state).

FIG. 37 is a diagram showing a situation in which ultraviolet-rayirradiation processing is performed.

FIG. 38 is a diagram showing the positional relationship between thestage and the head in the vertical direction.

FIG. 39 is a flowchart showing an operation according to a variation.

FIG. 40 is a diagram showing two objects to be pressurized according toanother variation.

FIG. 41 is a diagram showing two objects to be pressurized according tostill another variation.

FIG. 42 is a diagram showing two objects to be pressurized according toanother variation.

FIG. 43 is a diagram showing two objects to be pressurized according toanother variation.

FIG. 44 is a diagram showing two objects to be pressurized according toanother variation.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereafter, embodiments of the present invention will be described withreference to the drawings.

1. First Embodiment 1-1. Apparatus Structure

FIGS. 1 and 2 are side views showing the internal structure of a bondingapparatus 1 (also referred to as “1A”) according to a first embodimentof the present invention. Note that, for the sake of convenience,directions and the like are shown using an XYZ orthogonal coordinatesystem in the following figures.

The bonding apparatus 1 is an apparatus for bonding an object to bebonded 91 and an object to be bonded 92 together by disposing theobjects to be bonded 91 and 92 facing each other and applying pressureand heat thereto in a chamber (vacuum chamber) 2 under reduced pressure.Here a situation is assumed in which a substrate 91 and a chip(component) 92 are bonded together, more specifically, a situation inwhich pads (electrodes) 93 on the substrate 91 and metal bumps(electrodes) 94 on the chip 92 are bonded together, as shown in FIGS. 9and 10. So-called solder bumps formed of an appropriate solder materialcan be used as the metal bumps 94. Also, the metal bumps 94 are notlimited thereto, and may be formed of various types of metal materialssuch as gold (Au), copper (Cu), or aluminum (Al). Note that in FIG. 9and other figures, the pads 93 and the metal bump 94 are shown in anexaggerated manner for convenience of illustration.

Surface activation processing is performed in advance on bondingsurfaces of the objects to be bonded 91 and 92 (the pads 93 and themetal bumps 94). It is assumed here that an apparatus outside of thebonding apparatus 1 performs surface activation processing in advance onthe objects to be bonded 91 and 92, and thereafter the objects to bebonded 91 and 92 are carried into the bonding apparatus 1.

The surface activation processing is processing for activating thebonding surfaces of the objects to be bonded 91 and 92, and isimplemented by emitting a specific substance (e.g., argon) using a beamirradiation unit. The beam irradiation unit activates the bondingsurfaces of the objects to be bonded 91 and 92 by accelerating anionized specific substance (e.g., argon) in an electric field andemitting that specific substance toward the bonding surfaces of theobjects to be bonded 91 and 92. In other words, the beam irradiationunit activates the bonding surfaces of the objects to be bonded 91 and92 by irradiating the bonding surfaces of the objects to be bonded 91and 92 with energy waves. Examples of the beam irradiation unit includean atomic beam irradiation apparatus and an ion beam irradiationapparatus.

The bonding apparatus 1 is also referred to as a mounting apparatus forbonding the component 92 held by a head 22 and the substrate 91 held ona stage 12 together so that the component 92 is mounted on the substrate91. The bonding apparatus 1 is further referred to as a pressureapplication apparatus for applying pressure to the objects to bepressurized, namely the component 92 and the substrate 91, because thebonding between the objects to be pressurized is implemented by applyingpressure in this bonding apparatus 1.

The bonding apparatus 1 includes the vacuum chamber 2 serving as spacefor processing the objects to be bonded 91 and 92. The vacuum chamber 2is connected to a vacuum pump 5 via an exhaust pipe 6 and an exhaustvalve 7. The vacuum chamber 2 is evacuated to a vacuum as a result of asuction operation of the vacuum pump 5 reducing pressure in the vacuumchamber 2. The exhaust valve 7 enables adjustment of the degree ofvacuum in the vacuum chamber 2 through the operation of opening andclosing the valve and the operation of adjusting the exhaust flow.

The objects to be bonded 91 and 92 are placed between a pressure surface22 f (see FIG. 3) of the head 22 (which is also referred to as a“pressure application member”) and a pressure surface 12 f of the stage12 (which is also referred to as a “pressure application member”).Specifically, the object to be bonded 92 on the upper side is held bythe head 22 (more specifically, by an electrostatic chuck, a mechanicalchuck, or the like provided at the tip of the head). Similarly, theobject to be bonded 91 on the lower side is held on the stage 12 (morespecifically, by an electrostatic chuck, a mechanical chuck, or the likeprovided at the tip of the stage).

The head 22 is heated by a heater 22 h build in the head 22, and therebycan adjust the temperature of the object to be bonded 92 held by thehead 22. Similarly, the stage 12 is heated by a heater 12 h built in thestage 12, and thereby can adjust the temperature of the object to bebonded 91 on the stage 12. The head 22 is also capable of rapidlycooling the head 22 itself to around a room temperature TH1, using anair-cooled cooling apparatus or the like built in the head 22. The sameapplies for the stage 12. The heaters 12 h and 22 h (in particular, 22h) function as a heating unit (melting units) or the like that melts themetal bumps 94, and also function as a cooling unit (solidificationunit) or the like that cools and again solidifies the metal bumps 94.That is, the heaters 12 h and 22 h (in particular, 22 h) function as aheating/cooling unit that heats or cools the metal bumps 94.

These head 22 and stage 12 are both movably installed in the vacuumchamber 2.

The stage 12 is capable of moving (translating) in an X direction by aslide movement mechanism 14 (see FIG. 2). The stage 12 moves in the Xdirection between a standby position (in the vicinity of a position PG1)on the relatively left side in FIG. 2 and a bonding position (in thevicinity of a position PG2 that is immediately below the head 22) on therelatively right side. The slide movement mechanism 14 includes ahigh-precision position detector (linear scale), so the stage 12 ispositioned with high accuracy.

The head 22 is moved (translated) in X and Y directions (twotranslational directions parallel to a horizontal plane) by an alignmenttable 23, and is rotated in a θ direction (direction of rotation aboutan axis parallel to a Z axis) by a rotation drive mechanism 25. The head22 is driven by the alignment table 23 and the rotation drive mechanism25 based on, for example, results of position detection by a positionrecognition unit 28 described later, and an alignment operation isperformed in the X, Y, and θ directions. Moving the stage 12 and thehead 22 relative to each other in the respective directions (X, Y, and θdirections) (in short, a horizontal direction) that are along a planeperpendicular to the vertical direction (Z direction) in this wayenables the object to be bonded 91 held on the stage 12 and the objectto be bonded 92 held by the head 22 to be aligned in the horizontaldirection.

The head 22 is also moved (elevated or lowered) in the Z direction by aZ-axis up-down drive mechanism 26. Moving the stage 12 and the head 22relative to each other in the Z direction enables the object to bebonded 91 held on the stage 12 and the object to be bonded 92 held bythe head 22 to be brought into contact with each other and then bondedtogether under pressure. Note that the Z-axis up-down drive mechanism 26is also capable of controlling pressure applied at the time of bonding,based on signals detected by multiple pressure detection sensors (e.g.,load cells) 29 and 32 (32 a, 32 b, and 32 c).

FIG. 3 is a schematic perspective view showing the vicinity of the stage12 and the head 22. Note that, in FIG. 3, the stage 12, the head 22, andthe like are shown in a general shape (generally cylindrical shape) inorder to simplify the illustration.

As also shown in FIG. 3, the bonding apparatus 1 further includes threepiezoelectric actuators 31 (31 a, 31 b, and 31 c) and three pressuredetection sensors 32 (32 a, 32 b, and 32 c).

The three piezoelectric actuators 31 a, 31 b, and 31 c and the threepressure detection sensors 32 a, 32 b, and 32 c are provided between thehead 22 and the alignment table 23. To be more specific, the threepiezoelectric actuators 31 a, 31 b, and 31 c are fixed to the uppersurface of the head 22 at different positions (three positions that arenot on the identical straight line). More specifically, the threepiezoelectric actuators 31 a, 31 b, and 31 c are disposed at generallyequal intervals in the vicinity of the outer peripheral portion of thegenerally circular upper surface of the generally cylindrical head 22.The three pressure detection sensors 32 a, 32 b, and 32 c connect theupper end surfaces of their corresponding piezoelectric actuators 31 a,31 b, and 31 c and the lower surface of the alignment table 23. In otherwords, the three pressure detection sensors 32 a, 32 b, and 32 c aredisposed at three independent positions (positions that are not on theidentical straight line) in a plane parallel to the pressure surface ofthe head 22.

The three piezoelectric actuators 31 a, 31 b, and 31 c are extendable inthe Z direction independently from each other, and are capable of finelyadjusting the posture (specifically, the angles of posture around twoaxes (e.g., around X and Y axes)) and position (specifically,Z-direction position) of the head 22. The three pressure detectionsensors 32 a, 32 b, and 32 c are capable of measuring pressures appliedto the three positions (positions that are not on the identical straightline) in a plane parallel to the lower surface (pressure surface) 22 fof the head 22. By driving the three piezoelectric actuators 31 a, 31 b,and 31 c so as to equalize the pressures applied to the respectivepositions, it is possible to bond the objects to be bonded 91 and 92together while maintaining the lower surface 22 f of the head 22 (seeFIG. 2) and the upper surface (pressure surface) 12 f of the stage 12 inparallel with each other.

1-2. Position Recognition Unit

The bonding apparatus 1 also includes the position recognition unit 28that recognizes the horizontal positions (specifically, X-, Y-, andθ-positions) of the objects to be bonded 91 and 92.

As shown in FIGS. 1 and 2, the position recognition unit 28 includesimage capturing units (cameras) 28L, 28M, and 28N that acquire anoptical image of an object to be bonded or the like as image data. Theimage capturing units 28L, 28M, and 28N each include a coaxialillumination system. Note that light (e.g., infrared light) transmittedthrough the objects to be bonded 91 and 92, the stage 12, and the likeis used as light sources of the coaxial illumination systems of theimage capturing units 28M and 28N.

Here, as shown in FIGS. 4 and 5, marks for positioning (hereinafter,also referred to as “alignment marks”, for example) MK are added to theobjects to be bonded 91 and 92. For example, two alignment marks MK1 aand MK1 b (see FIG. 4) are added to the one object to be bonded 91, andtwo alignment marks MK2 a and MK2 b (see FIG. 5) are added to the otherobject to be bonded 92.

The operation of positioning the objects to be bonded 91 and 92(alignment operation) is executed by the position recognition unit(e.g., cameras) 28 recognizing the positions of the alignment marks MKadded to the objects to be bonded 91 and 92.

For example, as shown in FIG. 2, the image capturing unit 28L of theposition recognition unit 28 acquires an optical image of the object tobe bonded 91 present at the position PG1 as image data. Specifically,light emitted from the light source disposed above the outside of thevacuum chamber 2 is transmitted through a window 2 a of the vacuumchamber 2 and reaches the object to be bonded 91 (position PG1), wherethen the light is reflected. The light reflected by the object to bebonded 91 is transmitted again through the window 2 a of the vacuumchamber 2 and proceeds to reach the image capturing unit 28L. In thisway, the image capturing unit 28L acquires the optical image of theobject to be bonded 91 as image data. Then, the image capturing unit 28Lextracts the alignment marks MK1 (such as MK1 a) based on the imagedata, recognizes the positions of the alignment marks MK1, and byextension, recognizes the position of the object to be bonded 91.

Similarly, the image capturing unit 28M of the position recognition unit28 acquires an optical image of the object to be bonded 92 present atthe position PG2 as image data. Specifically, light emitted from thelight source disposed below the outside of the vacuum chamber 2 istransmitted through a window 2 b of the vacuum chamber 2 and reaches theobject to be bonded 92 (position PG2), where then the light isreflected. The light reflected by the object to be bonded 92(specifically, part of the object) is transmitted again through thewindow 2 b of the vacuum chamber 2 and proceeds to reach the imagecapturing unit 28M. In this way, the image capturing unit 28M acquiresthe optical image of the object to be bonded 92 as image data. Also, theimage capturing unit 28M extracts the alignment marks MK2 (such as MK2a) based on the image data, recognizes the positions of the alignmentmarks MK2, and by extension, recognizes the position of the object to bebonded 92.

As described above, a captured image GL is acquired by the imagecapturing unit 28L in a state in which the object to be bonded 91 ispresent in the vicinity of the position PG1, and a captured image GM isacquired by the image capturing unit 28M in a state in which the objectto be bonded 92 is present in the vicinity of the position PG2.Thereafter, the object to be bonded 91 is moved in the X directiontoward the vicinity of the position PG2, following the stage 12 beingmoved in the X direction by the slide movement mechanism 14.

In this case, the bonding apparatus 1 obtains the amounts of shift ofthe objects to be bonded 91 and 92 from their reference positionsrespectively based on the images GL and GM. Then, the bonding apparatus1 adjusts the amount of X-direction movement of the object to be bonded91, and adjusts the Y-direction position or the like of the object to bebonded 92, based on the amounts of shift. As a result, the object to bebonded 91 is moved to the position PG2, and accordingly the objects tobe bonded 91 and 92 have a substantially proper relative positionalrelationship in the horizontal direction in a state in which the objectsto be bonded 91 and 92 are spaced facing each other. Such a roughpositioning operation is also referred to as “rough alignment”.Alternatively, this positioning operation is also referred to as a“pre-alignment operation” because this is an alignment operationperformed prior to an even more precise alignment operation (which isalso referred to as a “fine alignment operation”) as described later.

The position recognition unit 28 is also capable of executing a positionmeasurement operation for fine alignment operation as described later.Specifically, in the state in which the objects to be bonded 91 and 92face each other, the position recognition unit 28 is also capable ofrecognizing the positions of the objects to be bonded 91 and 92, usingthe captured images (image data) GA of transmitted light and reflectedlight of illumination light emitted from the coaxial illuminationsystems of the image capturing units 28M and 28N. In other words, theoperation of positioning the objects to be bonded 91 and 92 (finealignment operation) is executed by the position recognition unit (suchas cameras) 28 simultaneously recognizing the positions of the two sets(MK1 a and MK2 a) and (MK1 b and MK2 b) of alignment marks added to theobjects to be bonded 91 and 92.

More specifically, as shown in FIG. 1, light emitted from the lightsource (not shown) of the coaxial illumination system of the imagecapturing unit 28M is reflected by a mirror 28 e and changes directionto travel upward. The light is further transmitted through the window 2b (FIG. 1) and a part (or the entirety) of the objects to be bonded 91and 92, then reflected by the marks MK1 a and MK2 a of the objects to bebonded 91 and 92, and this time travels in the opposite direction(downward). The light is then transmitted again through the window 2 band reflected by the mirror 28 e where the travelling direction ischanged to the left, and reaches an image sensor in the image capturingunit 28M. The position recognition unit 28 acquires the optical image(image including the marks MK1 a and MK2 a) of the objects to be bonded91 and 92 as a captured image GAa (see FIG. 6) in this way andrecognizes the positions of a given set of the marks (MK1 a and MK2 a)added to the objects to be bonded 91 and 92 based on the image GAa, aswell as obtaining positional shift amounts (Δxa and Δya) between themarks (MK1 a and MK2 a) of that set (see FIG. 7). FIG. 7 is a diagramshowing a state in which the marks MK1 a and MK2 a of a given set areshifted from each other.

Similarly, light emitted from the light source (not shown) of thecoaxial illumination system of the image capturing unit 28N is reflectedby the mirror 28 f where the travelling direction of the light ischanged, and travels upward. The light is further transmitted throughthe window 2 b (FIG. 1) and a part or the entirety of the objects to bebonded 91 and 92 and reflected by the marks MK1 b and MK2 b of theobjects to be bonded 91 and 92, and this time travels in the oppositedirection (downward). The light is then transmitted again through thewindow 2 b and reflected by the mirror 28 f where the travellingdirection of the light is changed to the right, and reaches an imagesensor in the image capturing unit 28N. The position recognition unit 28acquires the optical image (image including the marks MK1 b and MK2 b)of the objects to be bonded 91 and 92 as a captured image GAb (see FIG.6) in this way and recognizes the positions of the other set of themarks (MK1 b and MK2 b) added to the objects to be bonded 91 and 92based on the image GAb, as well as obtaining positional shift amounts(Δxb and Δyb) between the marks (MK1 b and MK2 b) of that set. Note herethat the operations of the image capturing units 28M and 28N acquiringthe captured images GAa and GAb are executed substantially at the sametime.

Thereafter, the position recognition unit 28 calculates relative shiftamounts (specifically, Δx, Δy, and Δθ) in the X, Y, and θ directionsbetween the objects to be bonded 91 and 92, based on the positionalshift amounts (Δxa, Δya) and (Δxb, Δyb) obtained for these two sets ofthe marks and the geometrical relationship between the two sets of themarks. Then, the head 22 is driven in the two translational directions(X and Y directions) and the rotation direction (θ direction) so as toreduce the relative shift amounts ΔD recognized by the positionrecognition unit 28. As a result, the objects to be bonded 91 and 92 aremoved relative to each other, and the above-described positional shiftamounts ΔD are corrected.

As described above, the positional shift amounts ΔD (specifically, Δx,Δy, and Δθ) in the plane (horizontal plane) perpendicular to thevertical direction (Z direction) are measured, and the alignmentoperation (fine alignment operation) of correcting the positional shiftamounts ΔD is executed. As will be discussed later, the operation ofmeasuring the positional shift amounts ΔD is executed in not only astate in which the objects to be bonded 91 and 92 are not in contactwith each other, but also a state in which the objects to be bonded 91and 92 are in contact with each other.

Note here that although the case where the two captured images GAa andGAb are acquired in parallel (substantially at the same time) using thetwo cameras 28M and 28N is given as an example, the present invention isnot limited thereto. For example, the captured images GAa and GAb may beacquired successively by moving a single camera 28M in the X and/or Ydirection(s).

1-3. Bonding Operation

Next is a description of an operation according to the first embodimentwith reference to FIG. 8. FIG. 8 is a flowchart showing the operationaccording to first embodiment. This operation is controlled by acontroller 100 (see FIG. 1) in the apparatus 1.

In FIG. 8, it is assumed that the aforementioned pre-alignment operation(rough alignment operation) has already been executed. After thepre-alignment operation, the objects to be bonded 91 and 92 are disposedfacing each other in a non-contact state.

Thereafter, the fine alignment operation (described above) is furtherexecuted in the non-contact state in steps S11 and S12.

Specifically, the captured images GAa and GAb (see FIG. 6) of theobjects to be bonded 91 and 92 (see FIG. 9) in the non-contact state areacquired in step S11. Then, the positional shift amounts (Δx, Δy, andΔθ) in the X, Y, and θ directions between the objects to be bonded 91and 92 are obtained based on the two captured images GA and GAb.

To be more specific, shift amounts (Δxa and Δya) are calculated using avector correlation method based on the image GAa obtained bysimultaneously reading the marks MK1 a and MK2 a that are spaced fromeach other in the Z direction. Similarly, shift amounts (Δxb and Δyb)are calculated using a vector correlation method based on the image GAbobtained by simultaneously reading the marks MK1 b and MK2 b that arespaced from each other in the Z direction. Then, the positional shiftamounts (Δx, Δy, and Δθ) in the horizontal direction between the objectsto be bonded 91 and 92 are measured based on the shift amounts (Δxa andΔya) and the shift amounts (Δxb and Δyb). Note that, as will bediscussed later, the positions can be obtained with higher accuracy ifthe image GAa including the marks MK1 a and MK2 a spaced from each otherin the Z direction is analyzed using the vector correlation method. Thesame applies for the image GAb.

Thereafter, the objects to be bonded 91 and 92 are moved relative toeach other so as to correct the positional shift amounts (Δx, Δy, andΔθ) in step S12. Specifically, with the stage 12 fixed, the head 22 ismoved in the X, Y, and θ directions so as to eliminate the positionalshift amounts (Δx, Δy, and Δθ). As a result, the objects to be bonded 91and 92 are horizontally aligned with extremely high accuracy (e.g.,within a tolerance of 0.2 micrometers). FIG. 9 is a schematic diagramshowing such a state. That is, FIG. 9 shows a state in which the objectsto be bonded 91 and 92 have a proper positional relationship in thehorizontal direction. Note that in FIG. 9, the objects to be bonded 91and 92 are spaced from each other in the vertical direction and are notyet in contact with each other.

Thereafter, in step S13, the head 22 is lowered by driving the Z-axisup-down drive mechanism 26 such that the objects to be bonded 91 and 92are brought into contact with each other (see FIG. 10). FIG. 10 shows asituation in which the objects to be bonded 91 and 92 are in contactwith each other while having a proper positional relationship in thehorizontal direction. Note that in this case, the contact pressurebetween the objects to be bonded 91 and 92 is adjusted to apredetermined value (e.g., 0.1 N/mm²) based on the result of detectionby the pressure detection sensor 29 or the like.

However, in actuality, the objects to be bonded 91 and 92 often fail tohave a proper positional relationship (FIG. 10) after such a contactoperation, as shown in FIG. 13. Even if the objects to be bonded 91 and92 have a proper positional relationship before their contact, such apositional shift that follows contact can occur due to factors such asthe action of physical impact force generated when the objects to bebonded 91 and 92 are brought into contact with each other.

In particular, such a positional shift can occur due to the followingfactor. Specifically, the objects to be bonded 91 and 92 at a time priorto contact may be disposed in a state (a state in which the objects aredisposed at an angle) that is different from an ideal state (a state inwhich the objects are disposed in parallel) as shown in FIG. 9. To bemore specific, there is a case, as shown in FIG. 11, where the stage 12and the head 22 (and by extension, the objects to be bonded 91 and 92)are disposed slightly at an angle to each other because the parallelismof the stage 12 and the head 22 is not enough.

In such a case, firstly, the object to be bonded 92 comes in contactwith the object to be bonded 91 on one end side in a predetermineddirection (e.g., the right side in the figure), following the downwardmovement of the object to be bonded 92, as shown in FIG. 12. Thereafter,the object to be bonded 92 moves in the horizontal direction (e.g., tothe right side in the figure) with respect to the object to be bonded 91along with a sliding motion at the portion where the objects are incontact, and at the same time, the object to be bonded 92 descends onthe other end side (e.g., the left side in the figure). In this way, therelative postures of the objects to be bonded 91 and 92 change graduallyso that the objects approach their parallel state, and the area ofcontact between the objects to be bonded 91 and 92 increases gradually.Note that, to be more specific, the contact operation and sliding motionof the objects to be bonded 91 and 92 are implemented by moving themetal bumps 94 of the object to be bonded 92 in contact with the pads 93(of the object to be bonded 91) facing the metal bumps 94. As a resultof these operations, the objects to be bonded 91 and 92 come intocontact with each other in a state in which they have a positional shiftin the horizontal direction as shown in FIG. 13.

Note here that the angled disposition of the objects to be bonded 91 and92 is given as an example of factors of a positional shift. However, inactuality, a positional shift as described above can occur due tovarious factors even if the objects to be bonded 91 and 92 are notdisposed at an angle to each other.

With the intention of resolving a post-contact positional shift asdescribed above, the bonding apparatus 1 of the present embodimentmeasures a positional shift in the horizontal direction between theobjects to be bonded 91 and 92, in a state in which the object to bebonded 91 and the object to be bonded 92 are in contact with each other.Then, the bonding apparatus 1 performs positioning of the objects to bebonded, by correcting that positional shift. With such an operation, itis possible to bond the objects to be bonded 91 and 92 together in astate in which the objects to be bonded 91 and 92 are even moreaccurately positioned in the horizontal direction.

Specifically, firstly, the captured images GAa and GAb (see FIG. 6) ofthe objects to be bonded 91 and 92 in a “contact state” (FIG. 13) areacquired in step S14 (FIG. 8). Then, the positional shift amounts (Δx,Δy, and Δθ) in the X, Y, and θ directions between the objects to bebonded 91 and 92 are measured based on the two captured images GAa andGAb.

Here, in the contact state of the objects to be bonded 91 and 92 (stepS14), the pads 93, which are raised portions on the surface of theobject to be bonded 91, and the metal bumps 94, which are raisedportions on the surface of the object to be bonded 92, are in contactwith each other. On the other hand, the marks MK1 provided on non-raisedportions of the surface of the object to be bonded 91 and the marks MK2provided on non-raised portions of the surface of the object to bebonded 92 are spaced from each other in the Z direction as shown in FIG.9 (or FIG. 11) or the like.

Then, also in step S14, similarly to step S11, the shift amounts (Δxa,Δya) are calculated using a vector correlation method based on the imageGAa obtained by simultaneously reading the two marks MK1 a and MK2 athat are spaced from each other in the Z direction. Similarly, the shiftamounts (Δxb, Δyb) are calculated using a vector correlation methodbased on the image GAb obtained by simultaneously reading the two marksMK1 b and MK2 b that are spaced from each other in the Z direction.Then, the positional shift amounts (Δx, Δy, and Δθ) in the horizontaldirections between the objects to be bonded 91 and 92 are measured basedon the shift amounts (Δxa, Δya) and the shift amounts (Δxb, Δyb).

Thereafter, if it is determined in step S15 that the positional shiftamounts fall within predetermined tolerances, the procedure proceeds tostep S16. Note that whether or not the positional shift amounts fallwithin predetermined tolerances may be determined based on, for example,whether or not the condition that all of the three positional shiftamounts (Δx, Δy, and Δθ) fall within their respective tolerances is met.

In step S16, the objects to be bonded 91 and 92 are moved relativelyaway from each other in the Z direction, so that the contact state ofthe objects to be bonded 91 and 92 is temporarily released (see FIG.14). To be more specific, the contact state of the objects to be bonded91 and 92 is released by elevating the head 22.

Then, in step S17, a positioning operation (alignment operation) isperformed in the non-contact state of the objects to be bonded 91 and92, that is, in a state in which the objects to be bonded 91 and 92 arefreely movable in the horizontal direction, by moving the objects to bebonded 91 and 92 relative to each other so as to correct the positionalshift amounts (Δx, Δy, and Δθ) (see FIG. 14). Specifically, with thestage 12 fixed, the head 22 moves in the X, Y, and θ directions so as toeliminate the positional shift amounts (Δx, Δy, and Δθ) (see the leftarrow in FIG. 14).

Thereafter, the procedure returns to step S13, in which the bondingapparatus 1 lowers the head 22 by driving the Z-axis up-down drivemechanism 26 such that the objects to be bonded 91 and 92 are againbrought into contact with each other.

Then, the operation in step S14, that is, the operation of measuring apositional shift between the objects to be bonded 91 and 92 in thecontact state, is performed again, and thereafter the procedure proceedsto step S15.

By executing the operations as described above (in particular, theoperation of measuring a positional shift in the contact state and thecorrection operation of correcting a positional shift) once orrepeatedly multiple times at a predetermined interval (e.g., one second)or the like, it is possible to reduce a positional shift due to thecontact operation itself between the objects to be bonded 91 and 92.Accordingly, the objects to be bonded 91 and 92, even in the final stateafter their contact, are horizontally aligned with extremely highaccuracy (e.g., within a tolerance of 0.2 micrometers) (see FIG. 10).

If it is determined in step S15 that a positional shift between theobjects to be bonded 91 and 92 falls within tolerance, the procedureproceeds to step S19.

In step S19, pressure as well as heat are applied to the objects to bebonded 91 and 92, as a result of which the objects to be bonded 91 and92 are bonded together. Specifically, the metal bumps 94 of the objectto be bonded 92 are heated and melt and thereby bonded to the pads 93 ofthe object to be bonded 91 in a state in which the metal bumps 94 are incontact with the pads 93. Thereafter, the state of applying pressure isreleased after the metal bumps 94 are solidified with the elapse of anappropriate cooling period. In this way, the objects to be bonded 91 and92 are favorably aligned with and bonded to each other.

As described above, with the operations of the present embodiment, it ispossible to align the objects to be bonded 91 and 92 with extremely highaccuracy because an actual positional shift in the contact state ismeasured and an alignment operation is performed so as to correct thatpositional shift. As a result, devices (semiconductor devices) or thelike that are configured by the objects to be bonded 91 and 92 and thelike can be manufactured with extremely high precision.

Furthermore, as mentioned above, the captured image GAa including boththe alignment mark MK1 a added to the object to be bonded 91 and thealignment mark MK2 a added to the object to be bonded 92 is acquired insteps S11 and S14 described above (see FIGS. 4 to 6). Similarly, thecaptured image GAb including both the alignment mark MK1 b added to theobject to be bonded 91 and the alignment mark MK2 b added to the objectto be bonded 92 is acquired. Then, a positional shift between theobjects to be bonded 91 and 92 is measured based on these capturedimages GA and GAb.

Here, the captured image GAa for position measurement is an imageacquired by simultaneously reading the alignment mark MK1 a added to theobject to be bonded 91 and the alignment mark MK2 a added to the objectto be bonded 92. Similarly, the captured image GAb for positionmeasurement is an image acquired by simultaneously reading the alignmentmark MK1 b added to the object to be bonded 91 and the alignment markMK2 b added to the object to be bonded 92.

If two alignment marks are separately read as two different images, anerror in the relative positions of the two images due to, for example, amatching error between the coordinate systems of the images can occurwhen detecting a positional shift between the two alignment marks. Forexample, in the case where the alignment mark MK1 a added to the objectto be bonded 91 is acquired as an image GC and the alignment mark MK2 aadded to the object to be bonded 92 is read in another image GD, anerror in shift amount between the two alignment marks MK1 a and MK2 acan occur due to, for example, a matching error between the coordinatesystem of the image GC and the coordinate system of the image GD. Inparticular, since the two images GC and GD are acquired at differentpoints in time, an error can also occur because the relative positionalrelationship between the two alignment marks MK1 a and MK2 a cannot beaccurately grasped due to various types of vibrations or like.

In contrast, with the example given in the above-described embodiment,the captured image GAa is an image acquired by simultaneously readingthe alignment marks MK1 a and MK2 a added to the objects to be bonded 91and 92. Accordingly, using that image GAa enables the occurrence of anerror as described above to be prevented. The same applies for the imageGAb.

Furthermore, in the above-described embodiment, in steps S11 and S14,the captured image GAa is acquired in a state in which the alignmentmarks MK1 a and MK2 a are spaced from each other in the Z direction, andthe edges of the portions corresponding to the alignment marks MK1 a andMK2 a in the captured image GAa are detected using the vectorcorrelation method.

FIG. 15 is a schematic diagram showing the mark MK1 a in a capturedimage (of a circular shape) acquired with a small amount of blurring,and FIG. 16 is a schematic diagram showing the mark MK1 a in a captureimage (of a circular shape) acquired with a relatively large amount ofblurring. With the vector correlation method according to the presentembodiment, a feature amount of an edge graphic (e.g., grayscaleinformation (direction of grayscale transitions) on an edge portion) isacquired in a vectorized form. Specifically, vectors each indicating achange in gradation from white to black are generated. Morespecifically, a vector directing from white to black is generated ateach portion of the ring-shaped mark MK1 a. For example, as can be seenfrom the comparison between FIG. 15 and FIG. 16, although the length ofeach vector in the case of a relatively large degree of blurring (FIG.16) is greater than that of each corresponding vector in the case of arelatively small degree of blurring (FIG. 15), the orientation of eachvector in FIG. 16 is the same as that of the corresponding vector inFIG. 15. Then, a comparison operation is executed, using primarilyinformation about the “orientations” of the vectors at the edge portionsin the images of the marks MK1 a and MK2 a. Accordingly, the influenceof the degree of blurring of the image is reduced as compared with thecase where the images of the marks MK1 a and MK2 a are compared on apixel by pixel basis.

As described above, using the vector correlation method enables theinfluence of the degree of blurring of images to be reduced andaccordingly enables the positions of the alignment marks to be detectedwith great accuracy. The same applies for the captured image GAb.

Furthermore, the image capturing units 28M and 28N of theabove-described embodiment each include a focal-position adjustmentmechanism for adjusting a position where light from an object forms animage. Such a focal-position adjustment mechanism is capable ofcapturing an image of an object present at a predetermined subjectdistance in an in-focus state by moving the lens position of aphotographing lens so that light from the object forms an image on animage capturing plane. The captured images GAa and GAb are each acquiredin, for example, the following in-focus state.

Specifically, the captured image GAa is acquired in a state in whichlight from a virtual object present at a Z-direction position MP (seeFIG. 17) between a Z-direction position PZ1 (PZ1 a) of the alignmentmark MK1 a and a Z-direction position PZ2 (PZ2 a) of the alignment markMK2 a forms an image on the image capturing plane of the image capturingunit 28M. Similarly, the captured image GAb is acquired in a state inwhich light from a virtual object present at a Z-direction position MPbetween a Z-direction position PZ1 (PZ1 b) of the alignment mark MK1 band a Z-direction position PZ2 (PZ2 b) of the alignment mark MK2 b formsan image on the image capturing area of the image capturing unit 28M.

By focusing on a point (preferably, the midpoint (middle)) between thealignment marks MK1 a and MK2 a in this way, it is possible to balancethe degrees of blurring of the alignment marks MK1 a and MK2 a (toprevent one of the marks from being blurred to a much greater degree)and to thereby detect a positional shift with high accuracy.

Furthermore, in the above-described embodiment, the contact operation instep S13 is (often) repeatedly executed multiple times on the objects tobe bonded 91 and 92 (specifically, the pads 93 and the metal bumps 94)that have undergone surface activation processing. With this contactoperation (pressure contact operation), an unnecessary re-adsorptionlayer present at the interface of bonding is broken through and removed,and therefore excellent activated bonding with reduced voids can beachieved at the interface of bonding. More specifically, excellentbonding is achieved by breaking through and removing such are-adsorption layer along with the contact operation and thereby causinga new surface under the re-adsorption layer to be exposed.

In general, two bonding surfaces each have relatively largeirregularities in microscopic view and are in contact with each other ata relatively small number of points. To break through the re-adsorptionlayer with only a single contact operation, a relatively high pressureis required because the re-adsorption layer needs to be broken throughwith a relatively small number of points (e.g., one point).

In contrast, in the above-described embodiment, in the case where thecontact operation in step S13 is repeatedly executed multiple times, there-adsorption layer is broken through and removed at a large number ofpoints with the re-contact operation of the objects to be bonded 91 and92 (step S13). This increases the number of contact points between thebonding surfaces of the objects and enables the objects to be bonded 91and 92 to be in contact with each other at a large number of points. Forexample, the objects to be bonded 91 and 92 are in contact with eachother at a relatively larger number of points immediately after thesecond contact operation, rather than immediately after the firstcontact operation. Accordingly, new surfaces are exposed at a largenumber of points, and as a result, excellent bonding is achieved. Inaddition, excellent bonding is possible with a relatively lower pressure(contact pressure) than in the case where only a single contactoperation is performed.

2. Second Embodiment

A second embodiment is a variation of the first embodiment. Thefollowing description focuses on differences from the first embodiment.

In the second embodiment, a case is illustrated in which an operation ofadjusting parallelism is also performed in accordance with thepost-contact measurement of a positional shift.

As mentioned above, there are cases where the stage 12 and the head 22are disposed at an angle to each other, and by extension, the objects tobe bonded 91 and 92 are disposed at an angle to each other (not inparallel with each other) as shown in FIG. 10, because the parallelismof the stage 12 and the head 22 is not enough. A shift or the like inthe contact state may increase due to such an angled disposition.

In view of this, in the second embodiment, the parallelism adjustmentoperation is also executed in accordance with the post-contactpositional shift measurement. Specifically, as shown in FIG. 18, theparallelism adjustment operation (step S22) is executed only once inaccordance with the post-contact positional shift measurement (stepS14). Note that FIG. 18 is a flowchart showing an operation according tothe second embodiment.

To be more specific, an operation of determining whether or not theparallelism adjustment operation (step S22) has already been executed isperformed in step S21 following step S14. If the parallelism adjustmentoperation has already been executed, the procedure proceeds from stepS21 to step S15. If the parallelism adjustment operation has not yetbeen executed, the procedure proceeds from step S21 to step S22. Here,it is assumed that the parallelism adjustment operation has not yet beenexecuted and the procedure proceeds to step S22.

FIGS. 19 to 21 are schematic diagrams showing the contact operation(step S13) performed in a state that involves deviation in parallelism.The operation in step S22 and the like will be described below withreference to these figures.

After the object to be bonded 92 that is inclined to the right as shownin FIG. 19 (see also FIG. 12) comes into contact with the object to bebonded 91 on the right side in the figures, the inclination anglebetween the objects to be bonded 91 and 92 decreases with a slidingmotion of the objects at the portion where the objects are in contactwith each other, and the objects to be bonded 91 and 92 are graduallybrought into contact with each other (see FIG. 20). Ultimately, in astate in which the objects to be bonded 91 and 92 are disposed inparallel and in contact with each other, a horizontal positional shiftbetween the objects to be bonded 91 and 92 reaches a value ΔD as shownin FIG. 21 (see also FIG. 13).

Here, assuming that there was no error ΔD (also denoted by ΔD0) (ΔD0=0)in the positional shift measurement operation performed in thenon-contact state (step S11), it is conceivable that a measurementresult ΔD (also denoted by ΔD1) obtained by the positional shiftmeasurement operation performed in the contact state (step S14) shows apositional shift amount that accompanies the sliding motion between theopposing surfaces. Thus, a difference (ΔD1−ΔD0) between the positionalshift ΔD0 between the objects to be bonded 91 and 92 in the “non-contactstate” and the positional shift ΔD1 between the objects to be bonded 91and 92 in the “contact state” is obtained as a positional shift amountDD that accompanies the sliding motion involved when the objects to bebonded 91 and 92 are brought into contact with each other.

Such a horizontal positional shift amount DD has a predeterminedrelationship with the inclination angle of the object to be bonded 92,in other words, a Z-direction shift amount ΔZ at an edge position of theobject to be bonded 92. FIG. 22 is a diagram showing the relationshipbetween the positional shift amount DD and the Z-direction displacementamount ΔZ. Note that the relationship shown in FIG. 22 may be obtainedin advance by experiment or the like.

Specifically, the positional shift amount DD that accompanies contactincreases with increasing pre-contact Z-direction displacement amount(comparative displacement from that in a parallel state) ΔZ at apredetermined position (right edge position in the figure) of the objectto be bonded 92. In other words, the positional shift amount DDincreases with increasing angle of inclination of the object to bebonded 92 to the object to be bonded 91. That is, the greater thepre-contact inclination angle between the objects to be bonded 91 and92, the more the objects to be bonded 91 and 92 are will shift at thetime of contact.

In the present embodiment, the parallelism of the objects to be bonded91 and 92 is adjusted based on the relationship between the positionalshift amount DD and the displacement ΔZ (FIG. 22) in step S22.Specifically, the Z-direction displacement ΔZ of the head 22 at aposition on one end side in the X direction is changed by appropriatelyadjusting the amounts of extension of the three piezoelectric actuators31 (31 a, 31 b, and 31 c). The posture of the object to be bonded 92relative to the objects to be bonded 91 and 92 is changed by, forexample, elevating the right edge position of the object to be bonded 92by the value ΔZ in the X direction as compared with the left edgeposition thereof. A similar posture adjustment operation may also beperformed in the Y direction. In this way, the posture of the head 22 ischanged so as to eliminate the displacement ΔZ corresponding to thepositional shift amount DD.

By changing the inclination angle of the head 22 using the piezoelectricactuators 31 in this way, the parallelism of the head 22 with respect tothe stage 12 is adjusted. As a result, the parallelism of the objects tobe bonded 91 and 92 in the non-contact state is adjusted.

Note that adjusting the parallelism of the objects to be bonded 91 and92 using the relationship between the positional shift amount DD and thedisplacement ΔZ can also be expressed to be measuring (estimating) theparallelism of objects to be bonded immediately before their contact,based on a positional shift between the objects to be bonded in thenon-contact state and a positional shift between the objects to bebonded in the contact state, and then controlling (adjusting) theparallelism of the objects to be bonded, based on the measurement result(estimation result).

Such a parallelism adjustment operation is executed in step S22 in FIG.18. Then, after the parallelism of the objects to be bonded 91 and 92has approximated its ideal state, the alignment operation in thenon-contact state in steps S11 and S12 is again performed. Thereafter,the contact operation in step S13 is again performed.

When the objects to be bonded 91 and 92 are again brought into contactwith each other (step S13) after the parallelism adjustment operation(step S22), an error due to the fact that the objects to be bonded 91and 92 are not in parallel with each other will be reduced. Accordingly,the positional shift amounts measured in the next step S14 are reducedas well. If it is determined in step S21 that the parallelism adjustmentoperation has already been executed, the procedure proceeds from stepS21 to step S15. In step S15 and the following steps, operations similarto those of the first embodiment are performed.

With the above-described operations, effects that are similar to thoseof the first embodiment can be achieved. In particular, in the secondembodiment, in step S22, the parallelism of the objects to be bondedimmediately before their contact is estimated based on the positionalshift between the objects to be bonded in the non-contact state and thepositional shift between the objects to be bonded in the contact state,and the parallelism of the objects to be bonded is controlled based onthe estimation result. Thereafter, the objects to be bonded 91 and 92are again brought into contact with each other. Accordingly, it ispossible to prevent needless force generated due to the fact thatobjects are not in parallel with each other from acting on the objectsat the time of their contact (re-contact) and accordingly to reduce, inparticular, post-contact (post-re-contact) positional shift amounts.

Note that in the second embodiment, the case is illustrated in which theparallelism adjustment operation in step S22 is performed only once(depending on the determination operation in step S21), but the presentinvention is not limited thereto. For example, the parallelismadjustment operation may be repeated several times. In this case, it ispossible to gradually reduce an error in parallelism.

3. Third Embodiment

In the first embodiment, the case is illustrated in which the objects tobe bonded 91 and 92 are temporarily brought out of contact with eachother by temporarily elevating the object to be bonded 92 in order toeliminate a post-contact positional shift, but the present invention isnot limited thereto. For example, the positioning of the objects to bebonded 91 and 92 may be performed by correcting a positional shiftbetween the objects to be bonded 91 and 92 while maintaining the contactstate of the objects to be bonded 91 and 92. The description of a thirdembodiment gives such a variation, focusing on differences from thefirst embodiment.

FIG. 23 is a flowchart showing an operation according to the thirdembodiment. As shown in FIG. 23, in the present embodiment, if it isdetermined that there is a positional shift of a predetermined amount ormore (step S15), the procedure proceeds directly to step S27, withoutinvolving the contact release operation in step S16 (FIG. 8).

In step S27, as shown in FIG. 24, horizontal positioning of the objectsto be bonded 91 and 92 is performed while maintaining the contact state(pressure contact state) of the objects to be bonded 91 and 92.Specifically, the positioning operation (alignment operation) isperformed by moving the head 22 in the horizontal direction(specifically, in the X, Y, and θ directions) so as to correct thepositional shift amounts (Δx, Δy, and Δθ) detected in step S14. As aresult, the positional shift amounts (Δx, Δy, and Δθ) are corrected.

Even with such an example, effects that are similar to those of theabove-described first embodiment can be achieved. Furthermore, the timerequired for the operation of releasing the contact state can be savedbecause the alignment operation of correcting a positional shift isexecuted while maintaining the contact state of the objects to be bonded91 and 92. Note that the example of the third embodiment is inparticular useful for cases such as where the contact area between theobjects to be bonded 91 and 92 is small (and/or the contact resistanceis small) or where the objects to be bonded 91 and 92 are easy to movein the contact state.

Furthermore, in the third embodiment, the objects to be bonded 91 and 92(specifically, the pads 93 and the metal bumps 94) that have undergonesurface activation processing slide while maintaining their contactstate. Executing such a sliding motion at least once (in particular,repeatedly multiple times) makes it possible to break through and removean unnecessary re-adsorption layer at the interface of bonding alongwith the sliding motion and to thereby achieve excellent activatedbonding with reduced voids at the interface of bonding. Morespecifically, as a result of the re-adsorption layer being brokenthrough and removed along with the sliding motion, new surfaces underthe re-adsorption layer are exposed, which enables excellent bonding tobe achieved.

As mentioned above, two bonding surfaces generally have relatively largeirregularities with a microscopic view and are in contact with eachother at a relatively small number of points. To break through are-adsorption layer with only application of vertical pressure without asliding motion, a relatively high pressure is required because there-adsorption layer needs to be broken through with a relatively smallnumber of points (e.g., one point).

In contrast, in the above-described third embodiment, if the horizontalmovement operation (pressure sliding motion) in step S27 is repeatedlyperformed, the re-adsorption layer will be broken through and removed ata larger number of points along with the sliding motion of the objectsto be bonded 91 and 92. This increase the number of contact pointsbetween the bonding surfaces of the objects and enables the objects tobe bonded 91 and 92 to be brought into contact with each other at alarger number of points. Such an operation enables new surfaces to beexposed at a large number of points, thus achieving excellent bonding.In addition, excellent bonding can be achieved with a relatively lowerpressure (contact pressure) than in the case that involves no horizontalmovement operation (pressure sliding motion).

4. Fourth Embodiment

In the above-described first and other embodiments, the case isillustrated in which the pads 93 and the metal bumps 94 after beingpositioned in their solid phase state, are heated and bonded to eachother.

The description of a fourth embodiment illustrates a case in which, in aheat-melt state in which the pads 93 and the metal bumps 94 are incontact with each other and the metal bumps 94 are being heated andmelted, positioning of the objects to be bonded 91 and 92 is performedby measuring and correcting a positional shift between the objects to bebonded 91 and 92, and after that positioning, the metal bumps 94 arecooled and solidified. That is, the case is described in which thealignment operation is executed in the heat-melt state of the metalbumps 94.

FIG. 25 is a flowchart showing an operation of the fourth embodiment.The following description is given with reference to FIG. 25, focusingon differences from the first embodiment.

Steps S31, S32, and S33 are operations respectively similar to those insteps S11, S12, and S13 (FIG. 8). In step S33, the objects to be bonded91 and 92 are brought into contact with each other and pressuretreatment is started (time T1), and in step S34, heat treatment isstarted.

FIG. 26 is a diagram showing a temperature profile according to thepresent embodiment. As shown in FIG. 26, a period TM51 (e.g.,approximately two seconds) from time T1 to time T2 is a temperature risestage, and the temperature of the head 22 rises to a temperature TH1during the period TM51. The temperature TH1 is a temperature higher thanthe melting point (melt temperature) MT of the metal bumps 94. A periodTM52 (e.g., approximately five seconds) from time T2 to time T3 is astage of maintaining temperature (fixed temperature stage), and thetemperature of the head 22 is maintained at the temperature TH1 duringthe period TM52. A period TM53 (e.g., approximately 15 seconds) fromtime T3 to time T4 is a cooling stage, and the head 22 is cooled toapproximately room temperature RT by an air-cooled cooling apparatus(cooling unit) or the like built in the head 22 during the period TM53.

In the fourth embodiment, in principle, a positional shift measurementoperation and re-alignment processing are executed during the fixedtemperature period TM52. If a positional shift amount ΔD falls within afirst tolerance RG1 (described later) during the fixed temperatureperiod TM52, cooling processing is executed immediately after the elapseof the period TM52 as shown in FIG. 26 (see the bold solid line in FIG.26). On the other hand, if the positional shift amount does not fallwithin the first tolerance RG1 even after the fixed temperature periodTM52 has elapsed, the positional shift measurement operation and there-alignment processing continue to be performed over an extended periodTM55 whose upper limit value is a predetermined period (e.g., threeseconds) (see the sold broken line in FIG. 26). Then, if the positionalshift amount ΔD falls within the first tolerance RG1 (described later)during the extended period TM55, cooling processing is immediatelyexecuted. Furthermore, if the positional shift amount ΔD falls within asecond tolerance RG2 after the elapse of the extended period TM55,cooling processing is immediately started. On the other hand, if thepositional shift amount ΔD does not fall within the second tolerance RG2even after the extended period TM55 has elapsed, error processing(exception processing) is executed. Note that the second tolerance RG2is set to be wider than the first tolerance RG1. For example, the firsttolerance RG1 for the X-direction position is defined to be a range of−0.2 micrometers to +0.2 micrometers, and the second tolerance RG2therefor is defined to be a range of −0.3 micrometers to +0.3micrometers. Similarly, the first tolerances RG1 and the secondtolerances RG2 for the Y-direction position and the θ-direction positionare also defined.

In step S35, standby processing is executed until the temperature risestage has ended (in other words, until the period TM51 has elapsed).During the standby processing period in step S35, processing at thetemperature rise stage in FIG. 26, that is, processing for heating andmelting the metal bumps 94, is executed. To be more specific, the metalbumps 94 are heated and melted in a state in which the metal bumps 94and the pads 93 (opposing portions) that face the metal pads 94 are incontact with each other.

Thereafter, in step S36, a positional shift measurement is performed inthe contact state of the objects to be bonded 91 and 92 and in theheat-melt state of the metal bumps 94. As shown in FIG. 27, if there isa positional shift amount ΔD that does not fall within the firsttolerance RG1 in the duration of the fixed temperature stage, theprocedure proceeds to step S39 via steps S37 and S38.

In step S39, horizontal positioning of the objects to be bonded 91 and92 is executed while maintaining the contact state of the objects to bebonded 91 and 92 and the heat-melt state of the metal bumps 94 (see FIG.28). Specifically, a positioning operation (alignment operation) isexecuted by moving the head 22 in the horizontal direction(specifically, in the X, Y, and θ directions) so as to correct thepositional shift amounts ΔD (Δx, Δy, and Δθ) detected in step S36. FIG.28 shows a situation in which the head 22 is moved in, for example, thedirection indicated by the white arrow. As a result, the positionalshift amounts (Δx, Δy, and Δθ) are corrected, and the objects to bebonded 91 and 92 transition to a state in which they have a properpositional relationship (see FIG. 29). In particular, in step S39 in thefourth embodiment, since the metal bumps 94 are in their melt state, itis possible to readily move the objects to be bonded 91 and 92 in thehorizontal direction while maintaining the contact between the metalbumps 94 and the pads 93 facing the metal bumps 94.

Thereafter, the procedure returns again to step S36, and the operationsfrom steps S36 to S39 are repeated. In this way, the positional shiftmeasurement operation performed in the contact state and the positionalshift correction operation performed while maintaining the contact stateare repeatedly executed during the period TM52. To be more specific,these operations are repeatedly performed every several hundredmilliseconds (ms), for example. Note that if the positional shiftamounts fall within the first tolerances RG1 during the fixedtemperature stage TM52, the procedure passes through steps S37 to S41and returns again to step S36, without executing the processing in stepS39.

Then, if it is determined in step S41 that the fixed temperature stageTM52 has ended, the procedure proceeds to step S43. In other words, ifit is determined, after the end of the fixed temperature stage TM52,that the positional shift errors fall within the first tolerances RG1,the procedure proceeds to step S43.

In step S43, cooling processing is performed by the cooling unit builtin the head 22, as a result of which the metal bumps 94 are cooled andsolidified. Then, after the elapse of the cooling period TM53 in FIG.26, a state in which pressure is applied to the objects to be bonded 91and 92 is released. With these operations, the objects to be bonded 91and 92 are favorably aligned with and bonded to each other.

Meanwhile, if the positional shift amounts ΔD do not yet fall within thefirst tolerances RG1 and the extended period TM55 after the end of thefixed temperature stage has not yet ended (specifically, the upper limitvalue for the extended period TM55 has not yet elapsed), the processingin step S39 is again executed via steps S37 and S38. In step S39,horizontal positioning of the objects to be bonded 91 and 92 is executedwhile maintaining the contact state of the objects to be bonded 91 and92 and the heat-melt state of the metal bumps 94 (see FIG. 28).

Also, if the positional shift amounts ΔD do not yet fall within thefirst tolerances RG1 even after the extended period TM55 after the endof the fixed temperature stage has ended, the procedure proceeds to stepS42 via steps S37 and S38. In step S42, it is determined whether or notthe positional shift amounts ΔD fall within the second tolerances RG2.

If the positional shift amounts ΔD fall within the second tolerancesRG2, the procedure proceeds to step S43, in which cooling processing isexecuted.

On the other hand, if the positional shift amounts ΔD are even out ofthe second tolerances RG2, the procedure proceeds from step S42 to stepS44, in which error processing (processing for removing a defectiveproduct) is executed.

With the above-described operations, the objects to be bonded 91 and 92can be aligned with extremely high accuracy because an actual positionalshift in the contact state is measured and the alignment operation ofcorrecting such a positional shift is performed as in the first andother embodiments.

Furthermore, the time required for the contact release operation can beshortened because the alignment operation of correcting the positionalshift is executed while maintaining the contact state of the objects tobe bonded 91 and 92.

Also, in particular, in the alignment operation that accompanies thecontact between the metal bumps 94 and the opposing pads 93, apositional shift can generally occur due to the impact force or the likegenerated at the time of contact between the metal bumps 94 and theopposing pads 93. Also, a positional shift that accompanies a phasechange of the metal bumps 94 from the solid phase to the liquid phasecan occur when the metal bumps 94 are heated and melted (in particular,at the temperature rise stage).

In contrast, in the fourth embodiment, a positional shift due to theimpact force or the like generated at the time of contact between themetal bumps 94 and the opposing pads 93 is favorably corrected, becausean actual positional shift is measured after the metal bumps 94 and theopposing pads 93 have come in contact with each other, and the alignmentoperation of correcting that positional shift is executed.

Furthermore, it is also possible to favorably correct even a positionalshift that accompanies a phase change of the metal bumps 94 from thesolid phase to the liquid phase, because an actual position after themetal bumps 94 have been heated and melted is measured and the alignmentoperation of correcting that positional shift is executed. Inparticular, in the above-described embodiment, a positional shift ismeasured after a predetermined period has elapsed since the start ofheating the metal bumps 94 (specifically, after the end of thetemperature rise stage). It is thus possible to favorably correct such apositional shift that may occur noticeably at the initial stage(temperature rise stage) immediately after the start of melting.

Note that the fourth embodiment illustrates the case in which theprocedure proceeds to step S43 after waiting for the end of the fixedtemperature stage TM52 in step S41, but the present invention is notlimited thereto. If the positional shift amounts ΔD fall within thefirst tolerances RG1, the procedure may proceed immediately to step S43(cooling processing) without waiting for the elapse of a predeterminedperiod (e.g., five seconds) of the fixed temperature stage TM52.

Furthermore, although the two tolerances RG1 and RG2 are defined in thepresent example, the present invention is not limited thereto. Forexample, if the positional shift amounts ΔD are out of predeterminedtolerances RG1 even after the fixed temperature period TM52 has elapsed,error processing or the like may be executed immediately.

Furthermore, although the case of providing the extended period TM55 isillustrated here, the present invention is not limited thereto. Forexample, if the end of the fixed temperature stage is determined in stepS38 (FIG. 25), the procedure may proceed to step S42 without providingthe extended period TM55 (in other words, by setting the extended periodTM55 to zero (seconds)).

5. Fifth Embodiment 5-1. Overview

Although the above-described embodiments illustrate the technique forbonding (applying pressure to) objects to be bonded (objects to bepressurized) in a state in which two portions, which are in the solidphase state prior to their contact, are in contact with each other, thepresent invention is not limited thereto. In this fifth embodiment, atechnique for applying pressure to two objects to be pressurized in astate in which a resin layer that is in a liquid phase state, prior tocontact is sandwiched between the objects is illustrated. To be morespecific, the case is illustrated in which the idea of the presentinvention is applied to so-called nanoimprint technology.

Although in the above-described second embodiment, the case isillustrated in which the parallelism of the objects to be bonded 91 and92 is adjusted based on the relationship between the positional shiftamount DD and the displacement ΔZ, the fifth embodiment illustrates atechnique for adjusting the parallelism of two objects to be pressurized81 and 82 based on measured values obtained by multipledistance-measuring sensors.

FIG. 30 is a diagram showing a pressure application apparatus 1 (alsoreferred to as “1E”) according to the fifth embodiment of the presentinvention. As shown in FIG. 30, the pressure application apparatus 1Ehas a similar configuration to that of the bonding apparatus (pressureapplication apparatus) 1A according to the first embodiment. Thefollowing description focuses on differences from the apparatus 1A.

As can be seen from the comparison between FIG. 30 and FIG. 1, theapparatus 1E differs from the apparatus 1A in that a UV (ultravioletray) irradiation unit 61 is included. Also, the apparatus 1E isconfigured to allow a mirror fixing member 28 g to be movable andretractable in the Y axis direction at the time of UV irradiation. Themirror fixing member 28 g is a member that fixes mirrors 28 e and 28 f.Note that this pressure application apparatus 1E is also referred to asa “nanoimprint apparatus”.

Here, a case is illustrated in which a semiconductor wafer serving asone object to be pressurized 82 is held by the head 22, and a mold(original plate) serving as the other object to be pressurized 81 isheld on the stage 12 (see FIG. 34). Also, a photo-curing resin has beenapplied in advance on the surface (lower surface) of the object to bepressurized 82. In other words, a resin layer 88 formed of aphoto-curing resin is provided on the underside of the object to bepressurized 82. Furthermore, the mold 81 is formed of a translucentmember (such as quartz), and an uneven pattern is provided on thesurface of the mold 81 (on the upper side in the figure). In short, themold 81 is a transparent mold.

Then, pressure is applied to the objects to be pressurized 81 and 82 ina state in which the resin layer 88 having fluidity is sandwichedbetween the objects to be pressurized 81 and 82 (see FIG. 36). To bemore specific, pressure is applied in a state in which the object to bepressurized 81, the resin layer 88, and the object to be pressurized 82are laminated one above the other in the order specified. In otherwords, pressure is applied to the objects to be pressurized 82 and 81with the resin layer 88 of a photo-curing resin sandwiched between theobjects. By pressing the uneven pattern of the mold 81 against the resinmaterial of the resin layer 88 in this way, the uneven pattern istransferred to the resin layer 88. In nanoimprint technology, apredetermined pattern is formed on the object to be pressurized 82 onthis principle.

The fifth embodiment describes a technique for measuring a positionalshift between the objects to be pressurized 81 and 82 in a state inwhich the mold 81 and the resin layer 88 (formed by being applied to theobject to be pressurized 82) are in contact with each other, andcorrecting that positional shift. The resin layer 88 is configured by asubstance that has fluidity (is fluidizable) during at least part of aperiod of applying pressure (in the present invention, also referred toas a “fluid substance” or “fluidizable substance”). The resin layer 88is also referred to as a “fluidizable substance layer”.

FIG. 31 is a schematic perspective view showing the vicinity of thestage 12 and the head 22 in the pressure application apparatus 1E.

As can be seen from the comparison between FIG. 31 and FIG. 3, thepressure application apparatus 1E further includes threedistance-measuring sensors 33 (33 a, 33 b, and 33 c) and threereflection plates 34 (34 a, 34 b, and 34 c), in addition to the threepiezoelectric actuators 31 (31 a, 31 b, and 31 c) and the three pressuredetection sensors 32 (32 a, 32 b, and 32 c).

The three distance-measuring sensors 33 a, 33 b, and 33 c are disposedat different positions P1, P2, and P3 that are not on the identicalstraight line in a plane parallel to the upper surface 12 f of the stage12 (a plane parallel to the XY plane) (see the plan view in FIG. 32).More specifically, the three distance-measuring sensors 33 a, 33 b, and33 c are fixed at approximately equal intervals on the outer peripheralside surface portion of the generally cylindrical stage 12 (see FIG.31). Also, the reflection plates 34 a, 34 b, and 34 c are fixedlyprovided at opposing positions corresponding respectively to thedistance-measuring sensors 33 a, 33 b, and 33 c on the outer peripheralside surface portion of the head 22.

For example, laser distance-measuring sensors can be used as thedistance-measuring sensors 33 a, 33 b, and 33 c. The distance-measuringsensors (e.g., laser distance-measuring sensors) 33 a, 33 b, and 33 cfixed to the stage 12 measure respective distances to the correspondingreflection plates 34 a, 34 b, and 34 c. Specifically, eachdistance-measuring sensor 33 emits laser light and measures a distance(distance between positions PZ1 and PZ2) DM from the distance-measuringsensor 33 to the corresponding reflection plate 34, using the laserlight (reflected light) reflected on the reflection plate 34 (see FIG.38). More specifically, each of the distance-measuring sensors 33 a, 33b, and 33 c measures the distance DM (DM1, DM2, or DM3) in the Zdirection between the Z-direction position PZ1 and the Z-directionposition PZ2, at each of the positions P1, P2, and P3 in the planeparallel to the XY plane. Note that the Z-direction position PZ1 is areference position in the Z direction of the distance-measuring sensor33 fixed to the stage 12, and the Z-direction position PZ2 is areference position in the Z direction of the reflection plate 34 fixedto the head 22 (see FIG. 38).

With this, it is possible to measure a spacing distance DA (see FIG. 38)in the Z direction between the objects to be pressurized 81 and 82. Anoperation of applying pressure involving such a measurement operationwill be discussed later. Note that, since the three distance-measuringsensors 33 a, 33 b, and 33 c measure the Z-direction distances DA at thethree positions P1, P2, and P3 as described above, it is possible tovery accurately measure the Z-direction position (relative position) andposture (relative posture) of the head 22 with respect to the stage 12.In other words, the relative positions and relative postures of theobjects to be pressurized 81 and 82 can be measured with great accuracy.

Furthermore, as will be discussed later, the objects to be pressurized81 and 82 can be held appropriately by, for example, approximating thesethree positions P1, P2, and P3 to the same target value.

5-2. Operation

FIG. 33 is a flowchart showing the operation according to the fifthembodiment. The operation of the fifth embodiment will be describedbelow with reference to FIG. 33, focusing on differences from theoperation of the third embodiment (FIG. 23). Note that the operations insteps S51 to S55 and S56 are respectively similar to those in steps S11to S15 and S27.

Firstly, as shown in FIG. 34, the objects to be pressurized 81 and 82are horizontally aligned with extremely high accuracy by the operationsin steps S51 and S52. Note that the objects to be pressurized 81 and 82are spaced from each other in the vertical direction, and the object tobe pressurized 81 and the resin layer 88 adhering to the object to bepressurized 82 have not yet been in contact with each other. Here, theresin layer 88 has been in a liquid phase state from the beginning andalready has fluidity prior to the operation of contacting the object tobe bonded 81 by lowering the head 22 (step S53).

Thereafter, in step S53, the head 22 is lowered by driving the Z-axisup-down drive mechanism 26, so that the object to be pressurized 81 andthe resin layer 88 of the object to be pressurized 82 are brought intocontact with each other (see FIG. 35).

A positional shift similar to that in the above-described firstembodiment can occur even immediately after the contact between theobject to be pressurized 81 and the resin layer 88. Specifically,immediately after the contact between the object to be pressurized 81and the resin layer 88, the objects to be pressurized 81 and 82 areoften shifted by a slight amount (ΔD) (in particular, in the horizontaldirection) from their proper positions due to a physical impact force orthe like generated at the time of the contact as shown in FIG. 35.

Also in the present embodiment, with the intention of resolving apositional shift due to contact as mentioned above, the pressureapplication apparatus 1 measures a positional shift in the horizontalposition between the objects to be pressurized 81 and 82 in a stateafter the object to be pressurized 81 and the object to be pressurized82 are brought into contact with each other (specifically, in a stateafter the object to be pressurized 81 and the resin layer 88 of theobject to be pressurized 82 are brought into contact with each other).Then, the pressure application apparatus 1 performs positioning of theobjects to be pressurized, by correcting that positional shift. Withsuch an operation, it is possible to apply pressure to the objects to bepressurized 81 and 82 in a state in which the objects to be pressurized81 and 82 are more accurately positioned relative to each other in thehorizontal direction. In particular, in the present embodiment, a caseis illustrated in which positioning of the objects to be pressurized 81and 82 is performed by correcting a horizontal positional shift whilemaintaining the contact state of the object to be pressurized 81 and theresin layer 88.

Specifically, firstly, captured images GAa and GAb (see FIG. 6) of theobjects to be pressurized 81 and 82 in the “contact state” (FIG. 35) areacquired in step S54. Then, positional shift amounts (Δx, Δy, and Δθ) inthe X, Y, and θ directions between the objects to be pressurized 81 and82 are measured based on the two captured images GA and GAb.

Thereafter, if it is determined in step S55 that the positional shiftamounts fall within tolerances, the procedure proceeds to step S57. Onthe other hand, if it is determined that the positional shift amountsare out of the tolerances, the procedure proceeds to step S56.

In step S56, horizontal positioning of the objects to be pressurized 81and 82 is executed while maintain the contact state (pressure contactstate) of the objects to be pressurized 81 and 82. Specifically, apositioning operation (alignment operation) is performed by moving thehead 22 in the horizontal direction (specifically, in the X, Y, and θdirections) so as to correct the positional shift amounts (Δx, Δy, andΔθ) detected in step S54. As a result, the positional shift amounts (Δx,Δy, and Δθ) are corrected. Thereafter, the procedure proceeds to stepS57.

In steps S57 to S59, a parallelism adjustment operation (also referredto as a “posture adjustment operation” or “inclination adjustmentoperation”) is also executed. Specifically, distances DMi are measuredat three different positions P1, P2, and P3, and multiple piezoelectricactuators 31 a, 31 b, and 31 c or the like are driven such thatdistances DAi between the object to be pressurized 82 and the object tobe pressurized 81 (see FIGS. 32 and 35) are equal to their desiredvalues TG (see FIG. 36). This realizes the operation of controlling thedistances DA (see FIG. 38) between the objects to be pressurized 81 and82 to predetermined values while disposing the objects to be pressurized81 and 82 in parallel with each other.

In step S57, each distance DAi between the objects is measured in thefollowing manner.

The pressure application apparatus 1E firstly measures the respectivedistances DM (specifically, DMi (i=1, 2, and 3)) at the three positionsP1, P2, and P3 (see FIG. 32), using the three distance-measuring sensors33 a, 33 b, and 33 c (see FIG. 38).

Next, a controller 100 of the pressure application apparatus 1Ecalculates the distance DA between the objects to be pressurized 81 and82, based on the measured distances DM and Equation (1).[Equation 1]DA=DM−(DE1+DT1+DT2+DE2)  (1)

Here, as also shown in FIG. 38, a value DE1 represents a displacement inthe Z direction (Z-direction distance) between a position PZ1 and apressure surface 12 f of the stage 12 (pressure application member), anda value DE2 represents a displacement in the Z direction (Z-directiondistance) between a position PZ2 and a pressure surface 22 f of the head22 (pressure application member). It is assumed that these values DE1and DE2 are known values measured in advance, and are stored in astorage unit in the controller 100 (FIG. 30) of the pressure applicationapparatus 1E.

Further, a value DT1 represents the thickness of the object to bepressurized 81 in the Z direction, and a value DT2 represents thethickness of the object to be pressurized 82 in the Z direction. Thesesthicknesses DT1 and DT2 of the objects to be pressurized 81 and 82,which have been measured in advance, are also stored in the storage unitin the controller 100.

The controller 100 performs calculation processing according to Equation(1) described above (or Equation (3) described later), based on dataregarding the values DE1 and DE2 and data DT1 and DT2 regarding thethicknesses of the objects to be pressurized 81 and 82 targeted forpressure treatment. Using such individual measured data regarding thethicknesses of the objects to be pressurized 81 and 82 targeted foractual processing in this way enables the distance DA between theobjects to be obtained with higher accuracy than in the case of usingtheoretical values for the thicknesses of the objects to be pressurized81 and 82.

Here, a distance DC between the pressure surface 22 f of the head 22 andthe pressure surface 12 f of the stage 12 is expressed by Equation (2)using the above-described values DE1 and DE2.[Equation 2]DC=DM−(DE1+DE2)  (2)

That is, by using the above-described values DE1 and DE2, measuring thedistance DM is equivalent to measuring the distance DC. In other words,measuring the distance DM with the distance-measuring sensors 33 isequivalent to measuring the distance DC with the distance-measuringsensors 33.

Taking Equation (2) into consideration, Equation (1) above can also beexpressed by Equation (3).[Equation 3]DA=DC−(DT1+DT2)  (3)

That is, the distance DA between the objects to be pressurized 81 and 82at a position Pi is calculated using the value DC and the values DT1 andDT2.

By using Equation (1) or Equation (3), the value DA is calculated basedon the measured distance value DM (or DC) and the thicknesses DT1 andDT2 of the two objects to be pressurized 81 and 82. In short, thedistance-measuring sensors 33 are capable of measuring the distance DAby measuring the distance DM (or DC).

In step S57, the distances DAi between the objects at three positions Piare calculated by performing the above-described calculation processingon the distances DMi measured at the three positions Pi. To be morespecific, the distances DAi at the three positions Pi are measured basedon the measured distances DMi, the values DT1 and DT2, and the valuesDE1 and DE2.

Thereafter, whether or not errors ΔEi (=TG−DAi) of the respectivedistances DAi between the objects with respect to the target value TGfall within tolerances is determined in step S58. If it is determinedthat the errors ΔEi fall within the tolerances, the procedure proceedsto step S60. On the other hand, if it is determined that any of theerrors ΔEi does not fall within the tolerance, the procedure proceeds tostep S59.

In step S59, the relative postures of the objects to be pressurized 81and 82 are corrected while maintaining the contact state (pressurecontact state) of the objects to be pressurized 81 and 82. Specifically,the three piezoelectric actuators 31 a, 31 b, and 31 c are driven suchthat the respective distances DAi approach their target values TG.Thereafter, the procedure proceeds to step S60.

In determination processing performed in the next step S60, it isdetermined whether or not a condition C1 for the immediately precedingmeasurement results (Δx, Δy, Δθ, and ΔEi) is met. This condition C1 isthat all of the positional shift amounts (Δx, Δy, and Δθ) in the XYplane between the objects to be pressurized 82 and 81 fall withintolerances and all of the errors ΔEi of the distances DAi between theobjects with respect to the target values TG fall within tolerances.

Then, if it is determined that the above-described condition C1 is notmet, the procedure returns again to step S54, where similar operationsare repeated. On the other hand, if it is determined that theabove-described condition C1 is met, the procedure proceeds to step S61.

If the positional shift measurement operation (step S54) and theoperation of measuring the distances DAi between the objects (step S57)each have been performed at least once and the condition C1 is met, itindicates that the positional shift amounts (Δx, Δy, and Δθ) in the XYplane are very small and the object to be pressurized 82 and 81 aredisposed in parallel with each other, as shown in FIG. 36. That is, theobjects to be pressurized 81 and 82 are disposed with great accuracy.

In step S61, the UV irradiation unit 61 apply ultraviolet (UV) rays in astate in which the objects to be pressurized 81 and 82 are disposed withgreat accuracy (see FIG. 37). The applied ultraviolet rays aretransmitted through the translucent mold 81 and reach the resin layer88. Accordingly, the photo-curing resin of the resin layer 88 that hadfluidity just before the UV irradiation is hardened. As a result, theresin layer 88 with a predetermined uneven pattern is formed on thesurface of the object to be pressurized 82, in a state in which theresin layer has the desired residual TG and is hardened.

Through the above-described processes, various types of devices (e.g.,semiconductor devices or MEMS (micro electro mechanical systems)devices) are manufactured with extremely high precision, usingnanoimprint technology.

In such an example, a horizontal positional shift due to the contactoperation itself between the objects to be pressurized 81 and 82 isreduced by the horizontal position adjustment operation in steps S54 toS56 or the like. Accordingly, the objects to be pressurized 81 and 82are horizontally aligned with extremely high accuracy in the finalpost-contact state (at the time of hardening or the like).

Furthermore, the respective distances DAi between the objects areaccurately controlled based on the values measured by thedistance-measuring sensors 33 a, 33 b, and 33 c in the inclinationadjustment operation in steps S57 to S59. Accordingly, it is possible tocontrol the thickness (residual) DA of the resin layer 88 to the desiredvalue TG while disposing the semiconductor wafer 82 and the mold 81 inparallel with each other. In particular, even if the resin layersandwiched between the objects to be pressurized has fluidity, it ispossible to dispose the objects to be pressurized 81 and 82 in properpostures (e.g., in parallel) relative to each other, as well as to moreaccurately control the distance between the objects to be pressurized.

Furthermore, in particular, according to the above-described example,the resin layer is hardened in a state in which both of the horizontal(X-direction, Y-direction, and θ-direction) positioning and thepositioning of the distances DAi between the objects (which is alsoreferred to as “vertical (Z-direction) positioning” or “inclinationadjustment operation”) have been performed. Accordingly, it is possibleto generate a three-dimensional molded component that has beenpositioned with high accuracy in both the horizontal and verticaldirections.

Note that in the above-described fifth embodiment, the case isillustrated in which the inclination adjustment operation (steps S57,S58, and S59) is performed only after the contact between the resinlayer 88 and the mold 81, but the present invention is not limitedthereto. For example, the inclination between the objects to bepressurized 82 and 81 may be adjusted in advance prior to the contactbetween the resin layer 88 and the mold 81. Specifically, an inclinationadjustment operation (similar to that in steps S57, S58, and S59) may beexecuted in the non-contact state between steps S52 and S53. Note thatthe target values for the distances DAi between the objects at this timeare preferably values TF (>TG) greater than the above-described valuesTG so that the resin layer 88 and the mold 81 will not yet be broughtinto contact with each other.

Furthermore, in the fifth embodiment, in obtaining each of the threedistances DAi at each position Pi, the same values DT1 and DT2 and thesame values DE1 and DE2 are used, but the present invention is notlimited thereto. For example, different values measured in a portion inthe vicinity of each position Pi may be used for the values DT1 and DT2and the values DE1 and DE2 in obtaining the distance at that positionPi.

Furthermore, although the fifth embodiment illustrates the case in whichan upper object to be pressurized and a lower object to be pressurizedare disposed in parallel with each other, the present invention is notlimited thereto. For example, the relative positional relationshipbetween the upper object to be pressurized and the lower object to bepressurized may be adjusted such that the three distances DAi betweenthe objects at the three positions P1, P2, and P3 reach (converge on)different target values.

Furthermore, although the above-described fifth embodiment illustratesthe case in which the above-described idea is applied to nanoimprinttechnology using a mold, the present invention is not limited thereto.For example, the above-described idea may be applied to the case wherepressure is applied to two substrates with a resin layer sandwichedtherebetween (see FIGS. 41 and 44 or the like, which will be discussedlater). In particular, a portion that has a liquid phase state, prior tocontact may be used as a resin layer in a manner similar to the fifthembodiment, and the above-described idea may be applied to a techniquefor applying pressure to two substrates with that resin layer sandwichedtherebetween.

7. Other Embodiments

While the above has been a description of embodiments of the presentinvention, the present invention is not intended to be limited to theabove-described content.

For example, an operation that combines the above-described secondembodiment and the above-described third embodiment may be executed asshown in FIG. 39. FIG. 39 illustrates an example in which step S27 (FIG.23) is executed, instead of steps S16 and S17 in FIG. 18.

Likewise, an operation that combines the above-described secondembodiment and the above-described fourth embodiment may be executed.Specifically, the parallelism adjustment operation or the like (seesteps S14 and S22 in FIG. 18) may be executed prior to the start of theheat treatment (step S34) in FIG. 25 (in other words, prior to themelting of the metal bumps 94).

Furthermore, although the above-described first to fourth embodimentsillustrate the case in which surface activation processing is performedin advance on the bonding surfaces of the objects to be bonded 91 and 92outside the above-described bonding apparatus 1, the present inventionis not limited thereto. For example, surface activation processing maybe performed in advance inside the bonding apparatus 1.

Furthermore, although the above-described first to fourth embodimentsillustrate a combination of a chip and a substrate as an example of theobjects to be bonded 91 and 92, the present invention is not limitedthereto. For example, the above-described idea is also applicable tobonding (bonding under pressure) of semiconductor wafers (silicon (Si)substrates). Specifically, the above-described idea is also applicableto the case of, as shown in FIG. 40, bonding semiconductor wafers 91 and92 in which thin films 95 and 96 made of gold (Au) are respectivelyformed on the bonding surface sides of the semiconductor wafers 91 and92. Alternatively, the above-described idea is applicable to the caseof, as shown in FIG. 41, bonding a semiconductor wafer 92 and a resinlayer 97 on the semiconductor wafer 91, the resin layer 97 having beenprovided in part on the semiconductor wafer 91 (specifically, thebonding surface thereof). As the resin layer 97, a thermosetting resinor a light curable resin can be used, for example. To be more specific,a horizontal positional shift is measured in a state in which both ofthe semiconductor wafers 91 and 92 are in contact with each other at aportion corresponding to the resin layer 97. Then, the resin layer 97may be hardened after the horizontal positional shift is corrected andthe semiconductor wafers 91 and 92 are bonded together. This enables theresin layer 97 to be precisely positioned in the horizontal directionand to be sealed, for example. Note that the operation of correcting ahorizontal positional shift is preferably performed while maintainingthe contact state of the semiconductor wafer 92 and the resin layer 97that has fluidity. Alternatively, the resin layer may be provided onboth of the bonding surfaces of the semiconductor wafers 91 and 92.Alternatively again, such a resin layer may be provided over the entiresurface of at least one of the objects to be bonded 91 and 92.Furthermore, the above-described idea is also applicable to a techniquefor applying pressure with a resin layer sandwiched not only between thesemiconductor wafers but also between various types of members.

Furthermore, although the above-described fifth embodiment illustratesthe case in which the inclination adjustment operation by thedistance-measuring sensors 33 or the like is applied to the techniquefor bonding (applying pressure to) two portions that include a portionbeing in a liquid phase state prior to their contact, by bringing theseportions into contact with each other, the present invention is notlimited thereto. For example, the inclination adjustment operation (theparallelism adjustment operation or the like) by the distance-measuringsensors 33 or the like is also applicable to the technique (first tofourth embodiments or the like) for bonding (applying pressure to) twoportions that have a solid phase state prior to their contact, bybringing these portions into contact with each other.

Furthermore, although the above-described fifth embodiment illustratesthe case in which a light-curable resin material is used as afluidizable substance, the present invention is not limited thereto. Itis sufficient that the “fluidizable substance” is a substance havingfluidity during at least part of the period of applying pressure, andmay, for example, be a thermosetting resin material or a metal such assolder. A configuration is also possible in which a post-contactpositional shift between the “fluidizable substance” and an object to bepressurized is corrected. Furthermore, the fluidizable substance may bea substrate that already has fluidity prior to contact (e.g., alight-curable resin material in the fifth embodiment), or may be asubstrate that does not have fluidity prior to contact and will havefluidity after contact (e.g., the metal bumps in the fourth embodiment).

The technique according to the aforementioned fifth embodiment or thelike is also applicable to a lens molding technique, for example.

For example, as shown in FIG. 42, the above-described idea is applicableto the case in which multiple lenses are formed on one surface of asubstrate (e.g., glass substrate) 72 by molding and hardening a resinlayer 73 on that surface of the substrate 72, using a mold 71 that hasmultiple concave portions formed in accordance with the respective lensshapes. In particular, using the above-described horizontal alignmenttechnique enables each lens to be accurately disposed at a predeterminedposition in the substrate. Furthermore, it is also possible toaccurately control the thickness of each lens by accurately controllinga vertical distance using distance-measuring sensors or the like as inthe above-described fifth embodiment.

Furthermore, lens may be formed on both front and rear surfaces of thesubstrate 72 with the application of the above-described idea (see FIG.43). Specifically, as shown in FIG. 43, it is possible to form multiplelens on the other surface of the substrate (e.g., glass substrate) 72 bymolding and hardening a resin layer 74 on the other surface of thesubstrate 72, using the above-described mold 71. In this case, by usingthe above-described horizontal alignment technique to form lenses onboth surfaces, it is possible to accurately dispose the lens provided onthe upper surface side of the substrate (also referred to “upperlenses”) and the lens provided on the lower surface side of thesubstrate (also referred to as “lower lens”) at predetermined positionsin the substrate. In particular, it is also possible to accurately alignthe horizontal positions of the optical axes AX of the upper lenses andthe horizontal positions of the optical axes AX of the lower lenses.

Furthermore, the above-described idea is also applicable to the casewhere, as shown in FIG. 44, multiple substrates 72 (72 a, 72 b) and 77formed as mentioned above (see FIG. 43) are laminated one above anotherin the direction of the optical axes of the lenses via a spacer 75 and aresin layer 76. This makes it possible to minimize shifts in opticalaxes between lenses in a given substrate and lenses in another substrate(e.g., shifts between the optical axes AX of the lenses in the uppersubstrate 72 a and the optical axes AX of the lenses in the lowersubstrate 72 b). Furthermore, it is also possible to accurately controlthe distance (e.g., a focal length) in the optical axis directionbetween multiple lenses disposed in the vertical direction (optical axisdirection), by accurately controlling the distances between the multiplesubstrates (e.g., the distance between the substrates 72 a and 72 b andthe distance between the substrates 72 b and 77).

Using such a technique enables generation of micro-machined componentsincluding lenses. In particular, hardening can be performed after twotypes of positioning (horizontal positioning and vertical positioning),namely, horizontal positioning (in the X, Y, and θ directions) andpositioning of the distances DAi between the objects (also referred toas “vertical positioning” or “posture adjustment operation”) have beenperformed. Accordingly, it is possible to generate a three-dimensionalmolded component that is positioned with high precision in bothhorizontal and vertical directions. Note here that the idea of thepresent invention that “pressure is applied to two objects to bepressurized” includes examples in which pressure is applied to three ormore objects to be pressurized (including two objects to be pressurized)as shown in FIG. 44.

Furthermore, in the above-described fifth embodiment, the case isillustrated in which the three distances DAi between the objects aremeasured based on the distances DMi measured by the threedistance-measuring sensors 33 a, 33 b, and 33 c, the values DT1 and DT2,and the values DE1 and DE2. In short, the case where the distances DAibetween the objects are indirectly measured is illustrated. However, thepresent invention is not intended to be limited thereto, and aconfiguration is also possible in which the distances DAi between theobjects may be directly measured. For example, a configuration ispossible in which, assuming that a first reflecting surface is providedon the surface of a glass mold and a second reflecting surface isprovided on the surface of a glass wafer, the distances fromdistance-measuring sensors provided on the underside of the glass moldto these two reflecting surfaces are measured, and a difference betweenthe two measured distances are calculated as the distances DAi betweenthe objects.

Furthermore, although the above-described embodiments illustrate thecase where the cameras 28M and 28N, each serving as an image capturingunit for fine alignment, are disposed at fixed positions, the presentinvention is not limited thereto, and images in the vicinity of twoalignment marks may be captured by moving a single camera.

Furthermore, although the above-described embodiments illustrate thecase where the stage 12 is moved in the X direction, the presentinvention is not limited thereto. For example, the stage 12 may befixed.

Furthermore, although the above-described embodiments illustrate thecase where the head 22 and the stage 12 are moved relative to each otherin the X, Y, Z, and θ directions by moving the head 22 in thesedirections, the present invention is not limited thereto. In contrast,for example, the head 22 may be fixed and the stage 12 may be moved inthe X, Y, Z, and θ directions such that the head 22 and the stage 12 aremoved relative to each other in these directions.

Furthermore, although the above-described embodiments illustrate thecase of movement in the X, Y, and θ directions in step S17, S27, or S56so as to eliminate the positional shift amounts ΔD (Δx, Δy, and Δθ), thepresent invention is not limited thereto.

For example, if the measurement results regarding a positional shiftfall within predetermined tolerances in step S17, S27, or S56,positioning may be performed by only movement in the X and Y directions(two translational directions parallel to a horizontal plane) withoutinvolving movement in the θ direction (the direction of rotation aroundthe axis parallel to the Z axis).

In general, in the case of involving movement in the θ direction, a newpositional shift can occur in the translational direction due to thatθ-direction movement.

In contrast, according to a variation such as described above, involvingonly movement in the translational direction at the final stage ofpositioning makes it possible to prevent the occurrence of such a newpositional shift, thus achieving efficient positioning.

Note that whether or not the measurement results regarding a positionalshift fall within predetermined tolerances may be determined based on,for example, whether or not the condition that all of the three shiftamounts (Δx, Δy, and Δθ) fall within their tolerances is met. However,the condition is not limited thereto, and whether or not the conditionthat some (e.g., only Δθ) of the three shift amounts (Δx, Δy, and Δθ)fall within tolerances is met may be based on to determine whether ornot the measurement results regarding a positional shift fall withinpredetermined tolerances.

Furthermore, although the above-described embodiments illustrate thecase of measuring the three horizontal positional shifts (Δx, Δy, andΔθ), the present invention is not limited thereto. For example, only thetwo horizontal shift amounts (Δx and Δy) may be measured. In this case,the image GAa may be acquired using only a single image capturing unit(e.g., 28M), and only positional shifts in the X and Y directions may bemeasured.

DESCRIPTION OF REFERENCE SIGNS

-   -   1 Bonding apparatus    -   2 Vacuum chamber    -   12 Stage    -   22 Head    -   22 h Heater    -   23 Alignment table    -   28L, 28M, 28N Image capturing unit (camera)    -   31 a, 31 b, 31 c Piezoelectric actuator    -   91, 92 Object to be bonded    -   93 Pad    -   94 Metal bump    -   95, 96 Thin film    -   97 Resin layer    -   GAa, GAb Captured image    -   MK1 a, MK1 b, MK2 a, MK2 b Alignment mark    -   ΔD, Δx, Δy, Δθ Positional shift amount    -   ΔZ Z-direction displacement amount

The invention claimed is:
 1. A pressure application apparatus thatapplies pressure to objects to be pressurized including a first objectto be pressurized and a second object to be pressurized, comprising:relative movement means for moving the first object to be pressurizedand the second object to be pressurized relative to each other in apredetermined direction; measurement means for measuring a positionalshift between the first object to be pressurized and the second objectto be pressurized in a plane perpendicular to the predetermineddirection, in a contact state in which the first object to bepressurized and the second object to be pressurized are in contact witheach other by the relative movement operation performed by the relativemovement means; alignment means for performing positioning of theobjects to be pressurized, by correcting the positional whilemaintaining the contact state of said first object and said secondobject to be pressurized; and heating/cooling means for heating/coolinga metal bump provided on the first object to be pressurized, in acontact state in which the metal bump is in contact with an opposingportion of the second object to pressurized that faces the metal bump,wherein the heating/cooling means heats and melts the metal bump in thecontact state of the metal bump and the opposing portion; wherein themeasurement means measures the positional shift in a first state that isthe contact state of the metal bump and the opposing portion as well asa state in which the metal bump is being heated and melted; wherein thealignment means performs positioning of the objects to be pressurized,by correcting the positional shift in the first state; and wherein theheating/cooling means cools and solidifies the metal bump after thepositioning has been performed.
 2. The pressure application apparatusaccording to claim 1, wherein the measurement means measures thepositional shift after a predetermined period of time has elapsed sincethe heating/cooling means starts heating the metal bump.
 3. The pressureapplication apparatus according to claim 1, wherein the measurementmeans measures the positional shift after a temperature state of themetal bump has reached a fixed temperature stage through a temperaturerise stage.
 4. A pressure application method for applying pressure toobjects to be pressurized including a first object to be pressurized anda second object to be pressurized, comprising the steps of: a) movingthe first object to be pressurized and the second object to bepressurized relative to each other in a predetermined direction suchthat the first object to be pressurized and the second object to bepressurized are brought into contact with each other; b) measuring apositional shift between the first object to be pressurized and thesecond object to be pressurized in a plane perpendicular to thepredetermined direction, in a contact state in which the objects to bepressurized are in contact with each other; and c) performingpositioning of the first object and second object to be pressurized, bycorrecting the positional while maintaining the contact state of theobjects to pressurized: wherein in the step b), the positional shift ismeasured in a first state that is a contact state in which a metal bumpprovided on the first object to be pressurized and an opposing portionof the second object to be pressurized that faces the metal bump are incontact with each other, as well as a state in which the metal bump isbeing heated and melted, and wherein the step c) comprises the steps of:c-1) performing positioning of the first object and second object to bepressurized by correcting the positional shift in the first state; andc-2) cooling and solidifying the metal bump after the positioning hasbeen performed.
 5. The pressure application method according to claim 4,wherein in the step b), the positional shift is measured after apredetermined period of time has elapsed since the heating of the metalbump is started.
 6. The pressure application method according to claim4, wherein in the step b), the positional shift is measured after atemperature state of the metal bump has reached a fixed temperaturestage through a temperature rise stage.
 7. A pressure application devicefor applying pressure to objects to be pressurized including a firstobject to be pressurized and a second object to be pressurized, with afluidizable substance layer sandwiched between the objects to bepressurized, the pressure application device comprising: relativemovement means for moving the first object to be pressurized and thesecond object to be pressurized relative to each other in apredetermined direction; first measurement means for measuring apositional shift between the objects to be pressurized in a planeperpendicular to the predetermined direction, in a contact state inwhich the first object to be pressurized and the fluidizable substancelayer adhering to the second object to be pressurized are in contactwith each other by the relative movement operation performed by therelative movement means; alignment means for performing positioning ofthe objects to be pressurized by correcting the positional shift whilemaintaining the contact state of the first object to be pressurized andthe fluidizable substance layer; and second measurement means formeasuring a distance in the predetermined direction between the objectsto be pressurized that are in the contact state, wherein in the contactstate, the relative movement means moves the first object to bepressurized and the second object to be pressurized relative to eachother such that the distance between the objects to be pressurizedapproaches a predetermined target value, on the basis of a result of themeasurement by the second measurement means.
 8. The pressure applicationdevice according to claim 7, wherein the second measurement meansmeasures the distance in the predetermined direction between the objectsto be pressurized that are in the contact state, at a plurality ofpositions in a plane whose normal direction is the predetermineddirection, and wherein in the contact state, the relative movement meansmoves the first object to be pressurized and the second object to bepressurized relative to each other such that the distances between theobjects to be pressurized at the plurality of positions each approach apredetermined target value, on the basis of a result of the measurementby the second measurement means.
 9. The pressure application deviceaccording to claim 8, wherein the second measurement means includesthree distance-measuring sensors and measures the distances between theobjects to be pressurized at three different positions that are not onan identical straight line in the plane, using the threedistance-measuring sensors.
 10. The pressure application deviceaccording to claim 7, wherein the first measurement means acquires acaptured image that includes alignment marks including a first alignmentmark added to the first object to be pressurized and a second alignmentmark added to the second object to be pressurized, and measures thepositional shift between the objects to be pressurized, based on thecapture image.
 11. The pressure application device according to claim 7,wherein the fluidizable substance layer already has fluidity when thefluidizable substance layer is brought into contact with the firstobject to be pressurized by the movement performed by the relativemovement means.
 12. The pressure application device according to claim7, wherein the fluidizable substance layer is a layer formed or a resinmaterial that is one of a thermosetting resin material and alight-curable resin material, wherein the first object to be pressurizedis a mold, and wherein the second object to be pressurized is asubstrate.
 13. A pressure application method for applying pressure toobjects to be pressurized including a first object to be pressurized anda second object to be pressurized, with a fluidizable substance layersandwiched between the objects to be pressurized, the pressureapplication method comprising the steps of: a) moving the objects to bepressurized relative to each other in a predetermined direction andbringing the first object to be pressurized and the fluidizablesubstance layer adhering to the second object to be pressurized intocontact with each other; b) measuring a distance in the predetermineddirection between the objects to be pressurized in a contact state inwhich the first object to be pressurized and the fluidizable substancelayer adhering to the second object to be pressurized are in contactwith each other; c) in the contact state, moving the first object to bepressurized and the second object to be pressurized relative to eachother so that the distance between the objects to be pressurizedapproaches a predetermined target value, on the basis of a result of themeasurement in the step b); d) in the contact state, measuring apositional shift between the objects to be pressurized in a paneperpendicular to the predetermined direction; and e) performingpositioning of the objects to be pressurized by correcting thepositional shift while maintaining the contact state of the first objectto be pressurized and the fluidizable substance layer.
 14. The pressureapplication method according to claim 13, wherein in the step b), thedistance in the predetermined direction between the objects to bepressurized that are in the contact state is measured at a plurality ofpositions in a plane whose normal direction is the predetermineddirection, and wherein in the step c), in the contact state, the firstobject to be pressurized and the second object to be pressurized aremoved relative to each other so that the distances between the objectsto be pressurized at the plurality of positions each approach apredetermined target value, on the basis of a result of the measurementin the step b).
 15. The pressure application method according to claim14, wherein in the step b), three distance-measuring sensors are used tomeasure the distances between the objects to be pressurized at threedifferent positions that are not on an identical straight line in theplane.
 16. The pressure application method according to claim 13,wherein the step d) includes the steps of: d-1) acquiring a capturedimage that includes alignment marks including a first alignment markadded to the first object to be pressurized and a second alignment markadded to the second object to be pressurized; and d-2) measuring thepositional shift between the objects to be pressurized, based on thecapture image.
 17. The pressure application method according to claim13, wherein the fluidizable substance layer already has fluidity whenthe fluidizable substance layer is brought into contact with the firstobject to be pressurized by the movement in the step a).
 18. Thepressure application method according to claim 13, wherein thefluidizable substance layer is a layer formed of a resin material thatis one of a thermosetting resin material and a light-curable resinmaterial, wherein the first object to be pressurized is a mold, andwherein the second object to be pressurized is a substrate.